Kevin Pietersen has polarised the flannelled world with his egocentricities in his dozen years as a professional cricketer. But as he prepared for his first Test match in his native Durban on Boxing Day, he also revealed a strong sense of probity.

His message – to adapt a long-running West End farce – appeared to be "No Swearing Please, I'm English". He has appealed to South Africans to strop swearing in front of children when he is on the field or signing autographs.

So far Pietersen has attracted only mild hostility here and he said: "The crowds have been fantastic and have respected good cricket, as they would all over the world.

"I've always said that I don't mind the booing. I don't mind being abused on the boundary. I find it quite fun and when you're in the field for a long day it can get boring, so it's good to have some sort of interaction with the crowd.

"The only thing that I don't like is when people swear and abuse me with swearing when there are kids around. And that's happened a couple of times on this tour and I've had to ask a few stewards to speak to people concerned.

"You can say what you like but when there are kids around there's no need to swear. That's poor. When you're signing things and people are swearing at you it's just not great for the kids."

He denied that it was impending fatherhood that had changed his thinking. "I've always felt like that," he said.

Not since the days of Brian Clough at Nottingham Forest has a sports personality been so anxious to take the blue out of the air. But with or without the swearing, Saturday will be a special day for Pietersen, who was born in nearby Pietermaritzburg 29 years ago.

It was in Natal that he emerged as a promising off-spinner, outstanding fielder and moderate late-order batsman. "Playing Test cricket for England is special, period, that's it – it doesn't matter whether it's here or Lord's or Faisalabad," he said with a shrug, trying to play down the significance of the occasion this weekend.

But he could not pretend for long: "I grew up here desperate to play international cricket. I remember watching New Zealand and Pakistan and the Aussies playing South Africa. And I remember England with , Jack Russell and Mike Atherton."

But by then Pietersen was already considering a future in English cricket. "I loved England and went over on holidays as everybody knows. I was looking to move and it was just after that tour [by England] that I decided to pack all the bags and make a life-changing decision which turned out to be fantastic."

Pietersen scored 81 in the second innings of the opening Test at Centurion on Sunday and it was the first time he had looked something like his old self since his previous Test match against Australia in the summer.

But his run-out, when going for a suicidal single, was followed by a batting collapse which almost led to an England defeat. With Pietersen, it seems, the impulsive must be accepted along with the brilliance. He described it as a silly mistake, his "brain-freeze moment".

Pietersen, though, has no trouble with the South Africa players. "I have a fantastic relationship with their players. I don't have a single problem on the field," he said. "I have played with [Mark] Boucher, [Jacques] Kallis, [Dale] Steyn, [Roelof] van der Merwe...all these guys in the IPL, and [Graeme] Smithy's calmed down and turned into a really good guy." A bit of a back-handed compliment, that last bit.